Conventionally, a well-known speed-changing device for a bicycle is constructed so that at one of an operating lever and a fixing member having a lever shaft supporting the operating lever is provided a ridge-groove surface, and the other of the lever and fixing member supports by a coiled spring a sound-generator engageable with the ridge-groove surface. The sound-generator is biased toward the ridge-groove surface by the spring, so that as the operating lever is turned it changes the engagement position of the sound-generator with the ridge-groove surface so as to intermittently generate a sound due to the engagement.
This conventional device has the ridge-groove surface directly on one of the operating lever and the fixing member. The sound-generator is formed separately from the coiled spring, so that upon assembling of the device the sound-generator and coiled spring are supported to one of the operating lever and the fixing member causing the sound-generator to engage with the ridge-groove surface. Hence, it is difficult to assemble or place the sound-generator unidirectionally biased by the coiled spring at a specific position to engage with the ridge-groove surface. It often happens that the sound-generator is moved away from the set position and the sound-generator or coiled spring unexpectedly falls off at the set position, resulting in a poor assembling efficiency or workability. Additionally, when speed-changing devices having respective different constructions are used for supporting operating levers having different constructions at the bosses thereof, the speed-changing devices cannot employ a common sound-generating mechanism comprising the ridge-groove surface and sound-generator biased by the coiled spring, so that each of the speed-changing devices needs its own specific sound-generating mechanism, which increases the costs to produce the various types of devices.